I wait each month to consume Concrete Construction and its wealth of information. I always learn something new! However, the December 2005 article "Concrete Pavement Construction Basics" excluded any reference to pozzolans in the discussion of durability, a glaring omission.

The author credits the managing director of technical services for the American Concrete Pavement Association (ACPA) with providing the “primer for basic fixed-form concrete pavement construction.” Perhaps a primer written in 1960 may not have referenced pozzolans, but a 2005 primer should.

In decades past, the Portland Cement Association was overly critical of the role of pozzolans in concrete mixes—until their members over a few decades secured ownership of pozzolan sources. Now the bias (which was for economic reasons) is all but gone within PCA, but apparently the ACPA is not as aware as it should be that it is OK now to acknowledge the many benefits of pozzolans in concrete mixes.

The “use of pozzolans to partially replace portland cement” should have been included in the sentence “Things that contribute to durability include ... ” at the very least.

Lynn Bergman
Bismarck, N.D